This invention broadly relates to a new fastener and more particularly the invention relates to a new fastener having a specially constructed and proportioned thread or shoulder and groove system.
Accordingly one object of the invention is to provide a new and improved fastener having a head and a shank portion and a collar member fastened thereon, in which fastener there are a plurality of specially designed and proportioned locking grooves.
Another object of the present invention is to provide a new fastener wherein the shoulder and groove shear area between the shank and the collar is divided proportionately in accordance with the respective strengths of the shank and collar constructional materials.
Another object of the present invention is to provide a novel fastener which includes a shoulder and groove shear area relationship that is proportioned in a predetermined manner and wherein the shoulder and/or groove construction is significantly non-uniform in dimension, when measured from the axial direction or the radial direction.
Another object of the present invention is to provide a new fastener having a plurality of proportioned strength shoulder and/or groove means which provide a substantially uniform load transfer to the shank portion of the fastener which is in contact with the collar member.
Another object of the present invention is to reduce fastener weight and to produce a fastener system that has greater tensile strength and less chance of fatigue or stress corrosion failures.
Other objects, features and advantages of the present invention will become apparent in the subsequent description and the appended claims taken in conjunction with the accompanying drawings.